|
|
| Elife. 2019 Feb 22;8. pii: e42148. doi: 10.7554/eLife.42148.
The impact of pathological high-frequency oscillations on hippocampal network activity in rats with chronic epilepsy.
Ewell LA1,2, Fischer KB1,3, Leibold C4,5, Leutgeb S1,6, Leutgeb JK1.
Author information
1Neurobiology Section and Center for Neural Circuits and Behavior, Division of Biological Sciences, University of California, San Diego, La Jolla, United States.2Institute of Experimental Epileptology and Cognition Research, University of Bonn Medical Center, Bonn, Germany.3Neuroscience Graduate Program, University of California, San Diego, La Jolla, United States.4Department Biologie II, Ludwig-Maximilians-Universität München, Martinsried, Germany.5Berstein Center for Computational Neuroscience Munich, Martinried, Germany.6Kavli Institute for Brain and Mind, University of California, San Diego, La Jolla, United States.
Abstract
In epilepsy, brain networks generate pathological high-frequency oscillations (pHFOs) during interictal periods. To understand how pHFOs differ from normal oscillations in overlapping frequency bands and potentially perturb hippocampal processing, we performed high-density single unit and local field potential recordings from hippocampi of behaving rats with and without chronic epilepsy. In epileptic animals, we observed two types of co-occurring fast oscillations, which by comparison to control animals we could classify as 'ripple-like' or 'pHFO'. We compared their spectral characteristics, brain state dependence, and cellular participants. Strikingly, pHFO occurred irrespective of brain state, were associated with interictal spikes, engaged distinct subnetworks of principal neurons compared to ripple-like events, increased the sparsity of network activity, and initiated both general and immediate disruptions in spatial information coding. Taken together, our findings suggest that events that result in pHFOs have an immediate impact on memory processes, corroborating the need for proper classification of pHFOs to facilitate therapeutic interventions that selectively target pathological activity.
www.ncbi.nlm.nih.gov/pubmed/30794155
|
| | |
